The principle of relative locality Speaker(s): Lee Smolin
Abstract: Several current experiments probe physics in the approximation in which Planck's constant and Newton's constant may be neglected, but, the Planck mass, is relevant. These include tests of the symmetry of the ground state of quantum gravity such as time delays in photons of different energies from gamma ray bursts. I will describe a new approach to quantum gravity phenomenology in this regime, developed with Giovanni AmelinoCamelia, Jersy KowalskiGlikman and Laurent Freidel.
This approach is based on a deepening of the relativity principle, according to which the invariant arena for nonquantum physics is a phase space rather than spacetime. Descriptions of particles propagating and interacting in spacetimes are constructed by observers, but different observers, separated from each other by translations, construct different spacetime projections from the invariant phase space. Nonetheless, all observers agree that interactions are local in the spacetime coordinates constructed by observers local to them.
This framework, in which absolute locality is replaced by relative locality, results from deforming momentum space, just as the passage from absolute to relative simultaneity results from deforming the linear addition of velocities. Different aspects of momentum space geometry, such as its curvature, torsion and nonmetricity, are reflected in different kinds of deformations of the energymomentum conservation laws. These are in principle all measurable by appropriate experiments.
Date: 23/02/2011  2:00 pm
Series: Colloquium
